Hi, In case, some of the list elements are vectors, this procedure would not work. a1<- list(c(3,5),4,5:6) as.numeric(a1) #Error: (list) object cannot be coerced to type 'double'
The OP didn't provide any info as to how the data looks like. So, these are just assumptions. mean(unlist(a1)) #if the overall mean is needed. #[1] 4.6 #or mean of each list element sapply(a1,mean) #[1] 4.0 4.0 5.5 #or if it includes data.frame or matrix. a2<- list(4, as.data.frame(matrix(1:10,5,2)),4:6) a3<- list(4, matrix(1:10,5,2),4:6) mean(unlist(a2)) #[1] 5.285714 mean(unlist(a3)) #[1] 5.285714 A.K. ----- Original Message ----- From: Albyn Jones <jo...@reed.edu> To: agnes69 <fes...@gredeg.cnrs.fr> Cc: r-help@r-project.org Sent: Friday, August 30, 2013 11:59 AM Subject: Re: [R] mean It would be easier to diagnose the problem if you included an example illustrating exactly what you did. I'll guess: > a <- list(3,4,5) > mean(a) [1] NA Warning message: In mean.default(a) : argument is not numeric or logical: returning NA > mean(as.numeric(a)) [1] 4 But that's just a guess, as I don't know the actual contents of your list! albyn On Fri, Aug 30, 2013 at 5:18 AM, agnes69 <fes...@gredeg.cnrs.fr> wrote: > When I try to apply mean to a list, I get the answer : > > argument is not numeric or logical: returning NA > > Could you help me? > > (I am a very beginner) > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/mean-tp4674999.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
